PROCESS FOR CONVERTING METHANOL TO ALKYL ETHERS, GASOLINE, DISTILLATE, AND ALKYLATE LIQUID HYDROCARBONS

摘要

A MULTISTAGE PROCESS FOR PRODUCING ISOALKYL ETHERS FROM LOWER ALIPHATIC OXYGENATE FEEDSTOCK, SUCH AS METHANOL. FEEDSTOCK IS CATALYTICALLY CONVERTED IN A PRIMARY CATALYST STAGE AT ELEVATED TEMPERATURE IN CONTACT WITH ZEOLITE CATALYST TO PREDOMINANTLY C2-C7 LOWER OLEFINS COMPRISING ISOBUTYLENE AND ISOAMYLENE, BY-PRODUCT WATER AND A MINOR AMOUNT OF C8+ HYDROCARBONS, FOLLOWED BY FRACTIONATION OF THE C2-C7 OLEFINS TO RECOVER A C2-C3-RICH RECYCLE STREAM FOR FURTHER CATALYTIC CONVERSION IN THE PRIMARY STAGE. C4-C7 OLEFINS ARE PASSED TO A SECOND CATALYTIC ETHERIFICATION STAGE FOR REACTION OF ISOALKENES WITH METHANOL TO PRODUCE METHYL TERTIARY-BUTYL ETHER, METHYL ISOAMYLETHER AND HIGHER ISOALKYL ETHERS.THE SECOND STAGE EFFLUENT MAY BE FRACTIONATED TO RECOVER AN ETHER PRODUCT, C5+ HYDROCARBON LIQUID PRODUCT, AND UNREACTED BUTENES. ADVANTAGEOUSLY, THE UNREACTED BUTENES ARE FURTHER REACTED WITH ISOPARAFFIN IN A THIRD CATALYST STAGE UNDER ACID CATALYSIS ALKYLATION CONDITIONS, AND FRACTIONATED TO RECOVER C6+ ALKYLATE LIQUID, LIQUID HYDROCARBON PRODUCT. THE ETHERS MAY BE BLENDED WITH AT LEAST ONE C6+ HYDROCARBON TO PRODUCE HIGH OCTANE GASOLINE.